1. Field of the Invention
The present invention relates to a device for installation in a hose and/or plastic pipe system and mounting of flow measurement sensors, having a plastic flow part as a hollow body with a centrally arranged and deformable region with a rectangular cross section, with two opposing sensor contact surfaces and two opposing pressure region surfaces being arranged on the outer surface of the centrally arranged region, and two connection regions for connecting to hoses and/or plastic pipes flanking the centrally arranged region. Moreover, the present invention relates to the use of the aforementioned device as well as to a method of flow measurement using the device.
2. Description of the Related Art
Flow measurements are performed in pipe and hose systems in a great number of processes in the automation of industrial or technical laboratory processes. To this end, flow meters are installed in all places in which the current delivery in the pipe or hose network is to be detected or the throughput is to be checked and further processed. Along with temperature, pressure and force, flow measurement constitutes one of the most important variables in industrial metrology and is an essential foundation of process automation.
In automated processes, the flow measurements vary depending on the method of measurement and the medium to be measured. A distinction is made between mechanical/volumetric, thermal, acoustic, magnetic/inductive, optical, gyroscopic or differential pressure/congestion methods. What all of the methods have in common, however, is the recording of certain physical characteristics, e.g., temperature, pressure, sound, acceleration, rotational speed, etc., via a measurement sensor.
In closed pipe or hose line systems, the flow measurements are divided into two subgroups based on medium and output signal, namely volumetric flow and mass flow. Furthermore, depending on the measurement setup, a distinction is made between so-called clamp-on flowmeters from in-line flow measurements. In the in-line flow measurements, the measurement sensors are mounted in the flow profile of the medium to be measured, whereas the clamp-on systems are placed from the outside onto the pipe or the hose and clamped.
Such a clamp-on system is described in JP 04940384 B1. It discloses an ultrasound flowmeter in which a hose through which the fluid to be measured flows is placed into a hinged measuring device and fixed in place by pressing the measuring device together. Through the deformation of the hose, the flow profile of the medium to be measured is altered into a nearly rectangular profile. However, as a result of fluctuations in the density and thickness of the hoses used as well as the resulting fluctuations in the internal cross section, severe measurement inaccuracies can occur when determining the volumetric flow. Both the reproducibility of the measurement results and the calibration of the overall system are thus also greatly impaired. What is more, the hose can bend or twist within the measurement unit during use or kink directly behind the measurement unit, which also leads to measurement inaccuracies.
For rigid pipe systems, a fixed component is known from U.S. Pat. No. 6,026,693 that can be installed into a pipe system via corresponding fittings or flanges. Pairs of ultrasound sensing elements are mounted on the rectangular-shaped component directly behind the flange regions from the outside. The fluid to be measured is changed by the component without transition from a round to an angular flow profile. As a result of the abrupt change from a round to an angular flow profile, turbulent flows are produced that can have a negative influence on the flow measurement. The rigid component is suitable for fixed pipelines having diameters from 2 to 24 inches. As a result of the structural unity of sensors and the actual flow component with a defined cross section, no variance is possible in relation to the sensing element to be connected on the one hand and the pipe diameter on the other hand.
It is therefore the object of the present invention to provide a device for flow measurement that is suitable for use in a plastic hose and/or plastic pipe system while avoiding the abovementioned drawbacks of the prior art. Moreover, it is the object of the present invention to provide a method of flow measurement using such a device.